As the electronics industry progresses, a variety of electronic products have become indispensable. Most electronic apparatuses are provided with function keys, through which different functions can be achieved. These function keys can be physical keys, or can be soft keys on a touch screen. Usually one function is achieved through only one function key. Taking a mobile phone for an example, turning on the power can only be achieved through the power on/off function key. Turning up the volume can only be achieved through the volume up function key, and lowering the volume can only be achieved through the volume down function key.